This invention relates to thiophenesulfonamides and their use as agricultural chemicals and particularly as herbicides.
U.S. Pat. No. 4,127,405 teaches compounds which are useful for controlling weeds in wheat having the formula ##STR1## wherein R.sub.1 is ##STR2## R.sub.3 and R.sub.6 are independently hydrogen, fluorine, chlorine, bromine, iodine, alkyl of 1-4 carbon atoms, alkoxy of 1-4 carbon atoms, nitro, trifluoromethyl, cyano, CH.sub.3 S(O).sub.n -- or CH.sub.3 CH.sub.2 S(O).sub.n --;
R.sub.4 is hydrogen, fluorine, chlorine, bromine or methyl; PA1 R.sub.5 is hydrogen, fluorine, chlorine, bromine, methyl or methoxy; PA1 R.sub.7 is hydrogen, fluorine, chlorine, bromine, alkyl of 1-2 carbon atoms or alkoxy of 1-2 carbon atoms; PA1 R.sub.8 is hydrogen, methyl, chlorine or bromine; PA1 R.sub.9 and R.sub.10 are independently hydrogen, methyl, chlorine or bromine; PA1 W and Q are independently oxygen or sulfur; PA1 n is 0, 1 or 2; PA1 X is hydrogen, chlorine, bromine, methyl, ethyl, alkoxy of 1-3 carbon atoms, trifluoromethyl, CH.sub.3 S-- or CH.sub.3 OCH.sub.2 --; and PA1 Z is methyl or methoxy; or their agriculturally suitable salts; provided that: PA1 R.sub.3 and R.sub.4 may independently be hydrogen, chlorine or alkyl of 1-4 carbon atoms. PA1 R is C.sub.1 -C.sub.4 alkyl, C.sub.3 alkenyl, OCH.sub.3, NO.sub.2, Cl, Br, SO.sub.2 NR.sub.1 R.sub.2 and SO.sub.2 N(OCH.sub.3)CH.sub.3 ; PA1 R.sub.1 and R.sub.2 are independently C.sub.1 -C.sub.3 alkyl; PA1 R.sub.3 is H or CH.sub.3 ; PA1 R.sub.4 is H, CH.sub.3 or OCH.sub.3 ; PA1 R.sub.5 is ##STR10## X is H, Cl, Br, CH.sub.3, CH.sub.2 CH.sub.3, C.sub.1 -C.sub.3 alkoxy, CF.sub.3, SCH.sub.3, CH.sub.2 OCH.sub.3, OCH.sub.2 CH.dbd.CH.sub.2 or OCH.sub.2 C.tbd.CH; PA1 Y is CH.sub.3 or OCH.sub.3 ; PA1 Z is CH, N, CCl, CBr, CCN, CCH.sub.3, CCH.sub.2 CH.sub.3, CCH.sub.2 CH.sub.2 Cl or CCH.sub.2 CH.dbd.CH.sub.2 ; PA1 Y.sup.1 is H, CH.sub.3, OCH.sub.3 or Cl; PA1 X.sup.2 and Y.sup.2 are independently CH.sub.3 or OCH.sub.3 ; and PA1 Q is O or CH.sub.2 ; and their agricultural salts; PA1 (a) A cannot be in the 4-position of the thiophene ring; and PA1 (b) one of R.sub.3 or R.sub.4 must be H; and PA1 (c) when A is in the 3-position and R is in the 2-position, then R is other than Cl, Br or CH.sub.3 where R.sub.5 is ##STR11## and Z is CH or N. PA1 R.sub.1 and R.sub.2 are independently C.sub.1 -C.sub.3 alkyl; PA1 (a) the sulfonyl isocyanate group cannot be in the 4-position of the thiophene ring; and PA1 (b) when the sulfonyl isocyanate is in the 3-position and R is in the 2-position then R is other than Cl, Br or CH.sub.3. PA1 R.sub.1 and R.sub.2 are independently C.sub.1 -C.sub.3 alkyl; PA1 (a) B may not be in the 4-position of the thiophene ring; and PA1 (b) when B is in the 3-position and R is in the 2-position, then R is other than Cl, Br or CH.sub.3.
(a) when R.sub.5 is other than hydrogen, at least one of R.sub.3, R.sub.4, R.sub.6 and R.sub.7 is other than hydrogen and at least two of R.sub.3, R.sub.4, R.sub.6 and R.sub.7 must be hydrogen; PA2 (b) when R.sub.5 is hydrogen and all of R.sub.3, R.sub.4, R.sub.6 and R.sub.7 are other than hydrogen, then all of R.sub.3, R.sub.4, R.sub.6 and R.sub.7 must be either chlorine or methyl; and PA2 (c) when R.sub.3 and R.sub.7 are both hydrogen, at least one of R.sub.4, R.sub.5 or R.sub.6 must be hydrogen.
French Pat. No. 1,468,747 discloses the following para-substituted phenylsulfonamides, useful as antidiabetic agents: ##STR3## wherein R=H, halogen, CF.sub.3 or alkyl.
Logemann et al. Chem. Ab., 53, 18052 g (1959), disclose a number of sulfonamides, including uracil derivatives and those having the formula: ##STR4## wherein R is butyl, phenyl or ##STR5## and R.sub.1 is hydrogen or methyl. When tested for hypoglycemic effect in rats (oral doses of 25 mg/100 g), the compounds in which R is butyl and phenyl were most potent. The others were of low potency or inactive.
Wojciechowski, J. Acta. Polon. Pharm. 19, p. 121-5 (1962) [Chem Ab., 59 1633 e] describes the synthesis of N-[(2,6-dimethoxypyrimidin-4-yl)aminocarbonyl]-4-methylbenzenesulfonamide: ##STR6## Based upon similarity to a known compound, the author predicted hypoglycemic activity for the foregoing compound.
Netherlands Pat. No. 121,788, published Sept. 15, 1966, teaches the preparation of compounds of Formula (i), and their use as general or selective herbicides, ##STR7## wherein R.sub.1 and R.sub.2 may independently be alkyl of 1-4 carbon atoms; and
Compounds of Formula (ii), and their use as antidiabetic agents, are reported in J. Drug. Res. 6, 123 (1974), ##STR8## wherein R is pyridyl.
The presence of undesired vegetation causes substantial damage to useful crops, especially agricultural products that satisfy man's basic food needs, such as barley, wheat, and the like. The current population explosion and concomitant world food shortage demand improvements in the efficiency of producing these crops. Prevention or minimizing the loss of a portion of such valuable crops by killing, or inhibiting the growth of undesired vegetation is one way of improving this efficiency.
A wide variety of materials useful for killing, or inhibiting (controlling) the growth of undesired vegetation is available; such materials are commonly referred to as herbicides. The need exists, however, for still more effective herbicides that destroy or retard weeds without causing significant damage to useful crops.